NASA is headed to Saturn's moon Titan, and it won't be scooting around on the surface. The Dragonfly mission is built around a nuclear-powered drone that will zip through the moon's thick atmosphere, covering much more ground than a wheeled explorer. Before NASA can launch the mission, it must ensure Dragonfly can fly on Titan. The agency has wrapped up a new round of wind tunnel testing, bringing us that much closer to the skies of Titan.
This won't be the first time NASA has flown in an alien environment—the Ingenuity Mars helicopter has surpassed all expectations and is still operating on the red planet. However, the environment on Mars is vastly different from Titan. Whereas Mars has a thin atmosphere of carbon dioxide, Titan's nitrogen atmosphere is almost 50% more dense than Earth's. NASA needs to ensure that Dragonfly can fly, NASA is testing its design at Langley Research Center in Virginia, which has a pair of wind tunnels perfect for putting the drone through its paces.
The final version of Dragonfly, which is expected to launch in 2027, will be the size of a small car. The current "Earth Demonstrator Drone" is half as large but uses the same stacked dual rotor design as the Titan explorer. The most recent testing began in June when the drone traveled from the Johns Hopkins Applied Physics Laboratory (APL) in Maryland to Langley.
In Langely's 14-by-22-foot Subsonic Tunnel, the team monitored the eight rotors during various simulated flight conditions. The Subsonic Tunnel was used to test Dragonfly's descent and transition to powered flight. In the Transonic Dynamics Tunnel (TDT), engineers gave the drone a taste of Titan's denser atmosphere. The team assessed the aeroshell's stability and the rotor aerodynamics at Titan-like pressure and air density in the TDT.
"We tested conditions across the expected flight envelope at a variety of wind speeds, rotor speeds, and flight angles to assess the aerodynamic performance of the vehicle," says Bernadine Juliano of APL. "We completed more than 700 total runs, encompassing over 4,000 individual data points. All test objectives were successfully accomplished and the data will help increase confidence in our simulation models on Earth before extrapolating to Titan conditions."
Titan is intriguing to study because it's the only known body in the solar system besides Earth with liquid reservoirs on its surface. It's not water, though. Titan's is so frigid that its surface is dotted with lakes of liquid hydrocarbons. NASA is keen to analyze this environment to better understand prebiotic chemistry. Titan is also one of the few moons with a thick atmosphere, which makes powered flight an efficient way to get around.
NASA has not decided on a launch vehicle for Dragonfly, but it may be waiting to see how Starship pans out. It'll need a powerful rocket to get Dragonfly to the Saturnian system. Assuming it launches in 2027, Dragonfly will land on Titan in 2034, where NASA hopes it will operate for three or four years.
